day 7

Cargo.toml

@@ -7,4 +7,5 @@ members = [
     "day4",
     "day5",
     "day6",
+    "day7",
 ]

day7/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "day7"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+petgraph = "0.6.2"

day7/sample_input.txt

@@ -0,0 +1,23 @@
+$ cd /
+$ ls
+dir a
+14848514 b.txt
+8504156 c.dat
+dir d
+$ cd a
+$ ls
+dir e
+29116 f
+2557 g
+62596 h.lst
+$ cd e
+$ ls
+584 i
+$ cd ..
+$ cd ..
+$ cd d
+$ ls
+4060174 j
+8033020 d.log
+5626152 d.ext
+7214296 ks

day7/src/main.rs

@@ -0,0 +1,76 @@
+use std::borrow::BorrowMut;
+
+use petgraph::*;
+use petgraph::dot::*;
+use petgraph::prelude::*;
+
+fn do_weights(g: &mut Graph<(String, u64), ()>, root_dir: NodeIndex<u32>) {
+    for edge in g.clone().edges_directed(root_dir, Outgoing) {
+        let mut target_weight = g.node_weight(edge.target()).unwrap();
+        if target_weight.1 == 0 {
+            do_weights(g, edge.target());
+            target_weight = g.node_weight(edge.target()).unwrap();
+        }
+        g.node_weight_mut(root_dir).unwrap().1 += target_weight.1;
+    }
+}
+
+fn main() {
+    const INPUT: &str = include_str!("../input.txt");
+
+    let mut g = DiGraph::<(String, u64), (), u32>::new();
+
+    let invalid_index: NodeIndex<u32> = NodeIndex::from(u32::MAX);
+    let mut curr_dir: NodeIndex<u32> = invalid_index;
+    let mut root_dir: NodeIndex<u32> = invalid_index;
+
+    for line in INPUT.lines() {
+        if line.starts_with("$ cd") {
+            let new_dir = &line[5..];
+
+            if new_dir == ".." {
+                curr_dir = g.edges_directed(curr_dir, Incoming).next().unwrap().source();
+            } else {
+                let prev_dir = curr_dir;
+                curr_dir = g.add_node((new_dir.to_string() + "/", 0));
+                if prev_dir == invalid_index { 
+                    root_dir = curr_dir;
+                } else {
+                    g.add_edge(prev_dir, curr_dir, ());
+                }
+            }
+        }
+        else if line.starts_with("$ ls") {
+            continue;
+        }
+        else {
+            let (size, name) = line.split_once(' ').unwrap();
+            if size == "dir" {
+                continue;
+            }
+
+            let size: u64 = size.parse().unwrap();
+
+            let n = g.add_node((name.to_string(), size));
+            g.add_edge(curr_dir, n, ());
+        }
+    }
+
+    do_weights(g.borrow_mut(), root_dir);
+
+    println!("{:?}\n\n", Dot::with_config(&g, &[Config::EdgeNoLabel]));
+
+    let total = g.node_weights().filter(|(n, w)| { n.ends_with("/") && *w <= 100000 }).map(|(_, w)| { w }).sum::<u64>();
+    println!("total: {total}");
+
+    let used_space = g.node_weight(root_dir).unwrap().1;
+    let free_space = 70000000 - used_space;
+    let need_to_free = 30000000 - free_space;
+
+    let mut delete = g.node_weights().filter(|(n, w)| { n.ends_with("/") && *w > need_to_free }).map(|(_, w)| { w }).collect::<Vec<&u64>>();
+    delete.sort();
+    let delete = delete[0];
+    println!("delete size: {delete}");
+
+
+}